Adenine or 6-aminopurine, is a naturally occurring product which is well known as an intermediate in the formation of various final products (see U.S. Pat. No. 3,846,246). It is known in the art that adenine may be prepared from 4,6-diamine-5-arylazopyrimidine [see Baddiley et al., "Jour. of the Chem. Soc." Part II (1943) pg. 386-387 and Cavalieri et al., "Jour. of the Am. Chem. Soc." Vol. LXXI (January-April 1949) pg. 533-536]. It is taught in Japanese patent publication No. 28497/73 application No. 62028/71 filed Aug. 17, 1971 and published April 14, 1973 that adenine may be prepared by a catalytic reduction of arylazomalononitrile in formamide in the presence of ammonia to obtain adenine in a single process step. It has been found, however, that the product resulting from said process leaves much to be desired in purity and yields. It has now been found that when a similar process is carried out in two stages, the yield and purity of the final product is substantially improved.